A positioning technology is a service for directly or indirectly obtaining geographic location information of a terminal by using a resource in a wireless communications network. OTDOA (Observed Time Difference of Arrival) positioning is a common terminal positioning method.
A principle of the OTDOA positioning is as follows: When three or more than three base stations exist in a wireless cellular network, a positioning server on a network side can determine a location of a terminal according to a time difference of arrivals, at the terminal, of downlink transmission signals sent by different base stations. FIG. 1 is a schematic diagram of a principle of OTDOA positioning in the prior art. As shown in FIG. 1, a serving base station of a cell in which a terminal 105 is located is a first base station 100, and a second base station 101 and a third base station 102 also exist in a wireless cellular network, where a distance of the terminal 105 to the first base station 100 is d0, a distance of the terminal 105 to the second base station 101 is d1, and a distance of the terminal 105 to the third base station 102 is d2; and the first base station 100, the second base station 101, and the third base station 102 may be selected as positioning base stations of the terminal 105. After the positioning server designates a sending and receiving configuration of a PRS (Positioning Reference Signal, positioning reference signal) for each positioning base station and the terminal, the three base stations sends a PRS to the terminal at the same time, and the terminal receives the PRS sent by each the positioning base station, and identifies a time location of a first-arrival path for each PRS. Then a time difference of arrivals of the PRSs of the different base stations may be obtained, and the time difference may be reported to the positioning server. The positioning server may map the time difference of the arrivals of the signals that are received by the terminal and sent by the different base stations to a difference of distances between the terminal and the different positioning base stations. Then it can be learned from a definition of a hyperbola that, points, a difference of whose distances to two fixed points is a constant value, constitute a hyperbola. For example, in FIG. 1, a difference between the distance of the terminal 105 to the first base station 100 and the distance of the terminal 105 to the second base station 101 is d1-d0, which corresponds to a first hyperbola 103; a difference between the distance of the terminal 105 to the second base station 101 and the distance of the terminal 105 to the third base station 102 is d2-d1, which corresponds to a second hyperbola 104; then, a point of intersection between the first hyperbola 103 and the second hyperbola 104 is a location of the terminal 105. When a quantity of base stations existing in the system increases, precision of terminal positioning can be improved.
At present, a multi-mode terminal has become a trend of terminal device development, for example, a terminal not only can support an ISM (Industrial Scientific & Medical) frequency band, but also can support an LIE (Long Term Evolution) frequency band. Some new interference may be introduced to the multi-mode terminal due to coexistence of the LTE frequency band and the ISM frequency band, for example, IDC (in-device coexistence) interference, interference caused by a WiFi (Wireless Fidelity) or Bluetooth signal transmitted by the terminal to reception of an LTE signal by the terminal, interference caused by an LIE signal sent by the terminal to reception of a GPS (Global Positioning System) signal by the terminal, and interference caused by an LIE signal sent by the terminal to reception of a WiFi or Bluetooth signal by the terminal.
Therefore, in an OTDOA positioning process, if there is an interference signal that affects positioning signal reception, measurement on a time difference of a arrivals of positioning signals is affected, and as a result, an error of terminal positioning is increased.